1. Field of the Invention
The present invention relates to a flat bed knitting machine with at least two carriages arranged on an elongated needle bed, the two carriages being reciprocally driven along the needle bed to produce knitted fabrics.
2. Description of the Related Art
Flat bed knitting machines generally include an elongated needle bed usually consisting of front and rear needle assemblies and a carriage which slides over the needle bed. With this arrangement, knitted fabrics can be knitted, the maximum width of which corresponds to the operative width of the needle bed. Typically, such flat bed knitting machines have a needle bed whose width is about 100 cm to 230 cm to accommodate the largest knitted fabric envisioned.
A single carriage provided on a needle bed has long been recognized as wasteful when the machine is only used to produce a knitted fabric of the maximum width. A solution that has been proposed provides two carriages on the needle bed, each carriage performing the same knitting task as the other carriage but at a separate areas of the needle bed. This permits two identical knitted fabrics to be produced, each having a maximum width of slightly less than one-half the operative width of the entire needle bed, that is, approximately 100 cm each. (The reduction from exactly one-half corresponds to the space which must be maintained between the knitted fabrics to insure that one carriage does not affect the stitches in the fabric knitted by the other carriage.)
For example, U.S. Pat. No. 4,640,103, issued to Hans Schreiber on Feb. 3, 1987, describes a double carriage flat bed knitting machine in which one carriage is selectably removable. When both carriages are present, the knitting stroke is shortened, thereby permitting two identical knitted fabrics to be produced. When only one carriage is present, the entire operative width of the needle bed is available for the production of a knitted fabric. This patent is said to provide the advantages of both a single- and a double-carriage knitting machine.
Whatever advantages might be obtained from the arrangement shown in U.S. Pat. No. 4,640,103, still only one knitted fabric, or two identical knitted fabrics, may be produced. This limits the type of knitted fabric that may be produced by such knitting machines to those fabrics producible by a single head, and makes production of certain weaves (for example, cabling and other complex stitch constructions) very difficult.